Condensor Fan A/C Mod

[tucsonjwt]

I added an auxiliary pusher fan to the 134a converted A/C on my 83 C20. It made a big difference in cooling at idle - not R12 quality but close.

I used a relay which had 12 ga. color coded wire hard wired in - so no need for extra spade connectors. I got a $35 condensor fan from a 1998 Chevy Metro at the pick and pull, since that was the only one I could find small enough to fit the opening (about 12".) I used about $40 in additional supplies, so about $75 total.

I mounted the fan with rubber grommets squished between the mounting tabs on the fan and the surface of the core support (like a rubber washer.) I was able to through bolt the one tab on the core support vertical, but used self-piercing screws on the two tabs on the opposite side.

I grounded the fan to the core support with the wiring and eyelet salvaged from the Metro. I used my secondary start battery on the driver's side for constant power (30 amp fuse), and used the fan clutch power wire for the "signal circuit" (5 amp fuse.) One wire went from the relay to power the fan, another wire from the relay went to ground at a screw inside the core support near the battery.

I used this graphic (page 3, "Single A/C Fan Only) as a guide:

http://www.davebarton.com/pdf/coolingfandiagrams.pdf